The Hum of the Whole Planet
Even when there are no earthquakes, the whole Earth is ringing, very quietly, all the time.
What was reported
In 1998, Japanese scientists studying data from a sensitive gravity meter at Syowa Station in Antarctica, and from seismometers around the world, reported something surprising. On days with no earthquakes at all, the planet was still vibrating, ringing at very low frequencies far below anything a human could hear.
The vibration, now called Earth's background hum, never stops. In 2017, scientists reported picking it up with seismometers on the floor of the Indian Ocean, showing it's everywhere.
Explanations offered
Most scientists now think the hum is driven by the oceans: long waves rolling across the sea and pounding on the sea floor, especially along continental shelves, set the whole planet ringing like a struck bell. The atmosphere may play a smaller part. How exactly the energy gets into the Earth is still being worked out.
- When
- Discovered in 1998
- Where
- Syowa Station, East Ongul Island, Antarctica
- Witnesses
- Japanese geophysicists and seismometers around the world
- Status
- Partly explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.
More from Antarctica